User interface for computed tomography (CT) scan analysis

ABSTRACT

An enhanced image is based on an original image. For instance, the original image can be processed using a filter to provide the enhanced image. The original and enhanced images can be displayed side by side or alternately to facilitate a comparison of the original and enhanced images. A user can change one or more enhancement parameters associated with the enhanced image. For example, the user can change the one or more enhancement parameters while viewing the original and enhanced images to determine an effect the change has on the enhanced image. The user can compare the effect of the changed enhancement parameters with his or her own analysis of the original image. The changed enhancement parameters may be applied to other parts of the original image so as to provide a more accurate analysis of those parts.

RELATED APPLICATIONS

This application claims the benefit of the filing date of GB PatentApplication No. 0420147.1, filed Sep. 10, 2004, which is incorporatedherein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to computed tomography (CT), andmore particularly to a user interface for displaying an enhanced CT scanimage.

2. Background

In conventional analysis of CT images, a radiologist visually inspectseach slice of a CT scan, using his or her expertise to identifyabnormalities and to distinguish them from normal structures. The taskcan be made easier by storing the scan image on a computer and providinga user interface that allows the user to move rapidly between slices andvisualize the structures in different ways. However, the process is timeconsuming and must be performed with great care to avoid overlookingabnormalities.

To replace some or all of the work of the radiologist, Computer AssistedDetection (CAD) software has been designed to analyze the scan image andto detect potential lesions. The detection of a lesion can be performedsemi-automatically, with some interaction with the radiologist, orautomatically, involving no interaction beyond the selection of theimage to be analyzed. For example, the applicant's MedicHeart™,MedicLung™, and MedicColon™ diagnostic software perform semi-automaticdiagnosis using CT scans of the heart, lung, and colon, respectively.

In practice, the results of CAD can be checked by a radiologist as asafeguard. If the software is used as the ‘first reader’, theradiologist generally only verifies the results produced by the softwareand does not analyze the original CT scan. To be effective as a ‘firstreader’, the software needs both high sensitivity (i.e., a lowpercentage of missed lesions) and high specificity (i.e., a lowpercentage of false positives), because the radiologist may makemedically important decisions based on the results. Using software as a‘first reader’ can save substantial time of the radiologist, thoughachieving both high sensitivity and high specificity can pose asignificant challenge.

Alternatively, the software can be used as a ‘second reader’, where theradiologist makes a preliminary diagnosis based on the original images,and then runs the software as a check for any missed lesions. When usedas a ‘second reader’, the software typically does not save time, but canassist the radiologist in making better diagnoses. The software does notneed to have particularly high sensitivity or specificity, so long as itleads to more accurate diagnoses than an unassisted radiologist. Used inthis way, the software is analogous to a spelling or grammar checker forword-processing. For instance, the software merely draws the user'sattention to oversights, rather than replacing the actions of the user.

What is needed is a user interface for analysis of CT scans that doesnot need to be as accurate as ‘first reader’ software and saves moretime than ‘second reader’ software.

PCT patent application WO 03/077203 discloses a user interface thatallows corresponding areas from different scans to be displayedside-by-side.

A further problem is that many CAD algorithms rely on a predefined setof parameter ranges for detection of abnormalities. For example theAgatston method, as originally described in ‘Quantification of coronaryartery calcium using ultrafast computed tomography’, Agatston A S,Janowitz W R, Hildner F J et al., J Am Coll Cardiol 1990 15:827-832,applies a threshold of 130 Hounsfield units (HU) to the CT image, andidentifies all pixels above that threshold as containing calcium. Ascoring system is then used to rate the severity of the calcification,based on the number of pixels above the threshold multiplied by a weightbased on the highest intensity within the calcification. If the highestintensity is between 130 and 200 HU, then the weight is 1; if between200 and 300 HU, the weight is 2; and if over 300 HU, the weight is 3.The values of the threshold and the weights are based on empiricalstudies of coronary scans and the subsequent outcome for the patients.However, there is continuing debate as to which parameter ranges givethe most accurate results. Different ranges may be appropriate fordifferent scan images.

U.S. Pat. No. 6,058,322 discloses an interactive user modificationfunction in which software displays detected microcalcifications and auser may then add or delete microcalcifications. The software modifiesits estimated likelihood of malignancy accordingly.

SUMMARY OF THE INVENTION

According to an embodiment of the invention, a method of displaying a CTscan image includes displaying an original scan image and displaying anenhanced scan image derived from the original scan image. The originaland enhanced images can be displayed with similar image attributes, suchas size and scale, to facilitate comparison between the original andenhanced images. The enhanced image may be enhanced to facilitateidentification of lesions or abnormalities in the original image.

In an embodiment, the original and enhanced images are displayedsimultaneously. In another embodiment, the original and enhanced imagesare displayed alternately with a similar size, scale, and position.

An advantage of these embodiments is that the original image can bevisually checked with respect to the enhanced image without the enhancedimage obscuring features of the original image. Instead of using theenhanced image as a first or second reader, the enhanced image acts as ajoint reader with a user. For example, the user can examine the originalimage while using the enhanced image for assistance.

According to an embodiment, the user is able to change enhancementparameters of the enhanced image while viewing the original and enhancedimages. For instance, the user can adjust the enhancement parameters toprovide suitable enhancement parameters. The user can adjust theenhancement parameters while observing the effect on the enhanced image.The user can compare the effect with the user's own analysis of theoriginal image. The adjusted enhancement parameters may be applied toother parts of the original image to provide a more accurate analysis ofthe other parts.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is described with reference to the accompanyingdrawings. In the drawings, like reference numbers indicate identical orfunctionally similar elements. Additionally, the left most digit(s) of areference number identifies the drawing in which the reference numberfirst appears.

FIG. 1 is a schematic diagram showing a CT scanner and a remote computerfor processing image data from the scanner and operating a userinterface according to an embodiment of the present invention.

FIG. 2 is a flow chart of the main steps of a method of operating a userinterface according to an embodiment of the present invention.

FIG. 3 illustrates a user interface having a sphericity enhancementfilter applied according to an embodiment of the present invention.

FIG. 4 shows a filter window of a user interface having a sphericityenhancement filter selected according to an embodiment of the presentinvention.

FIG. 5 illustrates a user interface having an edge enhancement filterapplied according to an embodiment of the present invention.

FIG. 6 shows a filter window of a user interface having a standard noiseremoval filter selected according to an embodiment of the presentinvention.

FIG. 7 shows a filter window of a user interface having an advancednoise removal filter selected according to an embodiment of the presentinvention.

FIG. 8 illustrates a user interface for use with colon scan imagesaccording to an embodiment of the present invention.

FIG. 9 illustrates an example computer system 900, in which the presentinvention may be implemented as programmable code.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION Scan Image

A computed tomography (CT) image can include a plurality of slices,which are generally obtained from a CT scan of a human or animalpatient. Each slice is a 2-dimensional digital grey-scale image of thex-ray absorption of the scanned area. The properties of the slice dependon the CT scanner used. For example, a high-resolution multi-slice CTscanner may produce images with a resolution of 0.5-0.6 mm/pixel in xand y directions (i.e., in the plane of the slice). Each pixel may have32-bit grayscale resolution. The intensity value of each pixel isnormally expressed in Hounsfield units (HU). Sequential slices may beseparated by a constant distance along a z direction (i.e., the scanseparation axis). For example, the sequential slices may be separated bya distance in a range of approximately 0.75-2.5 millimeters (mm).According to an embodiment, the scan image is a three-dimensional (3D)grey scale image, for example, with an overall size that depends on thearea and/or number of slices scanned.

The present invention is not restricted to any specific scanningtechnique, and is applicable to electron beam computed tomography(EBCT), multi-detector or spiral scans, or any technique that producesas output a 2D or 3D image representing X-ray absorption.

As shown in FIG. 1, the scan image is created by a computer 120.Computer 120 receives scan data from a scanner 110 and constructs thescan image based on the scan data. The scan image is often saved as anelectronic file or a series of files which are stored on a storagemedium 130, such as a fixed or removable disc. The scan image may bestored in a standard format, such as DIRCOM 3.0, for example. The scanimage may be processed by computer 120, or the scan image may betransferred to another computer 140 which runs software for processingand displaying the image as described below. The image processingsoftware may be stored on a computer recordable medium, such as aremovable disc, or downloaded over a network. Computer 120 or 140 can beany type of computer system, including but not limited to an examplecomputer system 900 described below with reference to FIG. 9.

User Interface Flowchart

FIG. 2 is a flow chart 200 of the main steps of a method of operating auser interface according to an embodiment of the present invention. Anoriginal scan image is provided as input at step 210. The original scanimage is processed at step 220 to provide an enhanced scan image. Arepresentation of the original scan image and the enhanced scan imageare displayed at step 230. The original and enhanced scan images can bedisplayed side by side or alternately, to provide some examples.

Parameter values can be associated with the enhanced scan image. Thedifference between the original scan image and the enhanced scan imagecan be based on the parameter values. For instance, the parameter valuescan affect processing the original scan image at step 220. The parametervalues can control detection sensitivity or other characteristics of theprocessing at step 220. A representation of the parameter values can bedisplayed with the original scan image and/or the enhanced scan image.

If a user input is not detected, as determined at step 240, flow returnsto step 240 to determine whether a user input is detected. Step 240 canbe repeated until a user input is detected. If a user input is detectedat step 240, the parameter values are adjusted at step 250. Flow returnsto step 220, where an enhanced scan image is produced using the adjustedparameters.

The original and enhanced scan images may be displayed side by side, ormay be displayed alternately at the same position and with the same sizeand scale, to provide some examples. For instance, the scan images canbe displayed alternately by alternately switching on and off the imageenhancement. The switching between original and enhanced images mayoccur in response to the user pressing a specific key or clicking on abutton displayed on-screen.

Lung Scan Embodiment

FIG. 3 illustrates a user interface 300 having a sphericity enhancementfilter applied according to an embodiment of the present invention. Inthe embodiment of FIG. 3, user interface 300 shows a two-dimensionalslice of a scan of a lung phantom. A lung phantom is a model thatapproximates a lung and contains objects having known properties. Forexample, the lung phantom can be used for testing and/or calibration.

In FIG. 3, user interface 300 is shown in a window that includes fourpanes 310 a-d, though the scope of the invention is not limited in thisrespect. The window can include any suitable number of panes 310. Anoriginal image pane 310 a displays a slice of the original scan image. Afirst toolbar 320 a is located at the bottom of original image pane 310a for illustrative purposes. First toolbar 320 a includes buttons thatallow the user to manipulate the original scan image. First toolbar 320a can facilitate zooming, panning, or rotating the original image, toprovide some examples.

Original image pane 310 a can include a first scroll bar 330 a. Forexample, first scroll bar 330 a can allow the user to scroll up or downwithin a slice of the original scan image. In another example, firstscroll bar 330 a can allow the user to move forward and/or backwardbetween slices of the original scan image.

An enhanced image pane 310 b displays a slice of the enhanced scanimage, which is a version of the original image processed by one or morefilters so as to highlight features of the original scan image. In theembodiment of FIG. 3, a sphericity enhancement filter is applied, andobjects satisfying the sphericity filter are circled. A second toolbar320 b in enhanced image pane 310 b includes buttons that allow the userto manipulate the enhanced scan image. The enhanced scan image can bemanipulated by zooming, panning, or rotating the enhanced scan image, toprovide some examples. Enhanced image pane 310 b includes a secondscroll bar 330 b to allow the user to scroll up or down within a sliceof the enhanced scan image or to move forward and/or backward betweenslices of the enhanced scan image.

First and second toolbars 320 may be linked so that an imagemanipulation performed using either toolbar 320 has a corresponding(e.g., equivalent) effect on both the original scan image and theenhanced scan image. For instance, a side-by-side comparison may be madebetween corresponding views of the original and enhanced scan images.For example, magnifying the original scan image using first toolbar 320a can magnify the enhanced scan image in enhanced image pane 310 b by anamount corresponding to the magnification of the original scan image. Inanother example, magnifying the enhanced scan image using second toolbar320 b can magnify the original scan image in original image pane 310 aby the same amount that the enhanced scan image is magnified in enhancedimage pane 310 b.

First and second scroll bars 330 may be linked, so that moving eitherscrollbar 330 has a corresponding (e.g., equivalent) effect on both theoriginal scan image and the enhanced scan image. Linking first andsecond scroll bars 330 can allow the user to move back and forth in thez-direction while comparing the original and enhanced scan images.

The window in which user interface 300 is shown includes a right-handtoolbar 340. Right-hand toolbar 340 displays options that are selectableby the user. In the embodiment of FIG. 3, options are categorized intoseven categories (Scans, Detector, Tools, Filter, Display, Report, andSystem) for illustrative purposes. For instance, the Display categoryincludes options that allow the user to control how many panes 310 aredisplayed in the window in which the user interface is shown. Theoptions in the Display category are Single, Double, Four, and Windowing.The window includes the number of panes 310 indicated by the option. Forexample, the window includes two panes 310 if the Double option isselected. In another example, panes 310 are displayed as separatewindows if the Windowing option is selected.

In FIG. 3, only two panes 310 a and 310 b are used for displaying scanimages, though the scope of the invention is not limited in thisrespect. Any suitable number of panes 310 can be used for displayingimages. In the embodiment of FIG. 3, third and fourth panes 310 c and310 d provide a data display function and a 3-dimensional (3D) noduledisplay function, respectively, for illustrative purposes.

One or more of the options shown in right-hand toolbar 340 can beassociated with sub-options. For example, selecting the Filters optionin the Filter category of right-hand toolbar 340 can allow the user toselect from multiple filter sub-options, as shown in filter window 350.The Filters option is highlighted in right-hand toolbar 340 to indicatethat the user selected the Filters option. Filter window 350 includingthe filter sub-options can appear in response to the user selecting theFilter option. In FIG. 3, the filter sub-options include Standard NoiseRemoval Filter, Advanced Noise Removal Filter, Spherical EnhancementFilter, and Edge Filter, each of which is indicated by a separate tab.The user can select a filter sub-option by selecting the correspondingtab. Accordingly, the user can select the type of filter to be appliedto the original scan image by selecting the tab that corresponds withthe associated filter sub-option. The filter sub-options can include anysuitable type of filter. The Filter option need not necessarily beassociated with sub-options.

The user can manipulate enhancement parameters associated with each ofthe filter sub-options. The user clicks the Apply button in filterwindow 350 to apply the filter associated with the selected filtersub-option. The enhanced image is updated based on the enhancementparameters of the filter selected by the user.

Filter window 350, filter sub-options and enhancement parametersassociated therewith are described in greater detail below withreference to FIGS. 4-7.

Sphericity Enhancement Filter

FIG. 4 shows filter window 350 of FIG. 3 having a sphericity enhancementfilter selected according to an embodiment of the present invention.Referring to FIG. 4, a Sphericity Enhancement Filter tab 410 ishighlighted to indicate that the user selected the SphericityEnhancement Filter sub-option. Filter window 350 having the SphericityEnhancement Filter sub-option selected includes controls 450 formanipulating enhancement parameters associated with the SphericityEnhancement Filter sub-option. In the embodiment of FIG. 4, filterwindow 350 includes a Spherical control 450 a, a Peak Hounsfield units(HU) control 450 b, a Nodule Size control 450 c, a Plural Tiny Nodulecontrol 450 d, and a Remove Cylindrical Shape control 450 e.

Spherical control 450 a includes a slider that allows the user to selecta minimum level of sphericity for objects passed by the filter. Peak HUcontrol 450 b includes a Min HU slider and a Maax HU slider. The Min HUand Max HU sliders allow the user to select a minimum peak intensity anda maximum peak intensity, respectively, within an object to be passed bythe filter. Nodule Size control 450 c allows the user to select one of aplurality of different size ranges of objects to be passed by thefilter. Plural Tiny Nodule control 450 d allows the user to selectwhether to detect plural tiny nodules in a scan image. RemoveCylindrical Shape control 450 e allows the user to select whether toremove cylindrical shapes from the scan image. For instance, RemoveCylindrical Shape control 450 e can provide the user with the ability toavoid enhancement of spherical shapes that are within cylindricalstructures, such as blood vessels.

The Sphericity Enhancement Filter can analyze each volume element(voxel) in a scan image and compare each voxel with surrounding voxelsof similar intensity to derive a 3-dimensional (3D) curvature of asurface of equal intensity. Surfaces having a sphericity exceeding avalue selected by the user (based on Spherical control 450 a) areidentified as belonging to spherical objects. Voxels contained withinthose surfaces are grouped together as parts of the same object. Onceall such objects have been identified, those having a maximum intensitybetween the Min HU and Max HU selected by the user (based on Peak HUcontrol 450 b), and a size within the range selected by the user (basedon Nodule Size control 450 c), are highlighted by the filter.

If a spherical object passed by the filter occupies multiple consecutiveslices, the object may be highlighted only on the slice that includesthe greatest area of the object.

Edge Enhancement Filter

FIG. 5 illustrates user interface 300 having an edge enhancement filterapplied according to an embodiment of the present invention. Referringto FIG. 5, an Edge Filter tab 420 is highlighted to indicate that theuser selected the Edge Filter sub-option. The Edge Filter sub-option canfacilitate identifying signs of interstitial disease such asreticulation. In the embodiment of FIG. 5, filter window 350 having theEdge Filter sub-option selected does not include controls formanipulating edge enhancement parameters. A contrast setting window 510can appear in response to the user selecting Edge Filter tab 420.Contrast setting window 510 can allow the user to vary contrastparameters of the edge enhancement filter. According to an embodiment,edge enhancement is applied to a lung parenchyma area only.

Standard Noise Removal Filter

FIG. 6 shows filter window 350 having a standard noise removal filterselected according to an embodiment of the present invention. Referringto FIG. 6, a Standard Noise Removal Filter tab 430 is highlighted toindicate that the user selected the Standard Noise Removal Filtersub-option. Filter window 350 having the Standard Noise Removal Filtersub-option selected includes a Blur control 610 for manipulatingenhancement parameters associated with the Standard Noise Removal Filtersub-option.

Blur control 610 includes a slider that allows the user to vary thedegree of noise smoothing to be applied to a scan image. The standardnoise removal filter is advantageous for reading low-dose MultipleSource Correlator Tracker (MSCT) studies, where radiation dose reductioncan be achieved at the expense of increased background noise. Thestandard noise removal filter is used in a standard noise reductiontechnique to smooth the background noise to the degree set by the user.

Advanced Noise Removal Filter

FIG. 7 shows filter window 350 having an advanced noise removal filterselected according to an embodiment of the present invention. AnAdvanced Noise Removal Filter tab 440 is highlighted in FIG. 7 toindicate that the user selected the Advanced Noise Removal Filtersub-option. Filter window 350 having the Advanced Noise Removal Filtersub-option selected includes a window size selector 710 to allow theuser to select the size of the window used to display informationrelating to an advanced noise reduction technique. The advanced noisereduction technique includes using the advanced noise removal filter toreduce noise associated with a scan image. For instance, the advancednoise reduction technique can provide less apparent blurring, ascompared to the standard noise reduction technique described above withrespect to FIG. 6. The advanced noise reduction technique may be moretime consuming than the standard noise reduction technique.

Colon Scan Embodiment

FIG. 8 illustrates user interface 300 being used with scan images of acolon according to an embodiment of the present invention. Differenttypes of scan images can be associated with different types of filters.For example, FIGS. 3-7, which are associated with the lung embodiment,show filter window 350 having different filter sub-options than filterwindow 850 shown in FIG. 8, which is associated with the colon scanembodiment.

In the embodiment of FIG. 8, a single polyp filter is available, ratherthan the choice of filters available in the lung scan embodiment.Filters available in different embodiments need not necessarily bedifferent. For instance, any of the filters available in the lung scanembodiment may be available in the colon scan embodiment, and viceversa. Some elements shown in FIG. 8 are similar to correspondingelements of FIG. 3 and share common reference numerals. Descriptions ofthese elements are not repeated with reference to FIG. 8.

Filter window 850 displays settings for the polyp filter. The polypfilter highlights raised objects with a spherical element, but does nothighlight objects that are elongated and likely to be folds. Filterwindow 850 includes minimum and maximum flatness sliders 810 a and 810b, respectively, which allow the user to select the degree of flatness(or a range thereof) of an object to be highlighted. For example, anobject can be highlighted if the degree of flatness of the object isgreater than a first degree specified by minimum flatness slider 810 aand less than a second degree specified by maximum flatness slider 810b.

In the embodiment of FIG. 8, user interface 300 includes a secondoriginal image pane 310 c and a second enhanced image pane 310 d. Secondoriginal image pane 310 c and original image pane 310 a show a supineaxial view and a prone axial view, respectively, of the original scanimage. Second enhanced image pane 310 d and enhanced image pane 310 bshow a supine axial view and a prone axial view, respectively, of theenhanced scan image. Toolbars 830 a and 830 b of second original imagepane 310 c and second enhanced image pane 310 d, respectively, can belinked, such that a change made in one of second original image pane 310c and second enhanced image pane 310 d is also made in the other.

Toolbars 330, 830 of any one or more image panes 310 can be linked, suchthat manipulating a toolbar 330, 830 to provide a change in one pane canresult in a corresponding change in the other of the any one or moreimage panes 310.

Single View Embodiment

As an alternative to the side-by-side views described above withreference to FIGS. 3, 5, and 8, the user may select a display mode inwhich only a single scan image view is displayed in the user interfacewindow. For instance, the enhancement selected in the filter window canbe switched on and/or off by the user, for example, by toggling a buttonin the filter window. Image display parameters can remain unchanged whenswitching between the original scan image and the enhanced scan image,which can allow the user to easily compare the original scan image andthe enhanced scan image.

Example Computer System

FIG. 9 illustrates an example computer system 900, in which the presentinvention may be implemented as programmable code. Various embodimentsof the invention are described in terms of this example computer system900. After reading this description, it will become apparent to a personskilled in the art how to implement the invention using other computersystems and/or computer architectures.

Computer system 900 includes one or more processors, such as processor904. Processor 904 may be any type of processor, including but notlimited to a special purpose or a general purpose digital signalprocessor. Processor 904 is connected to a communication infrastructure906 (for example, a bus or network). Various software implementationsare described in terms of this exemplary computer system. After readingthis description, it will become apparent to a person skilled in the arthow to implement the invention using other computer systems and/orcomputer architectures.

Computer system 900 also includes a main memory 908, preferably randomaccess memory (RAM), and may also include a secondary memory 910.Secondary memory 910 may include, for example, a hard disk drive 912and/or a removable storage drive 914, representing a floppy disk drive,a magnetic tape drive, an optical disk drive, etc. Removable storagedrive 914 reads from and/or writes to a removable storage unit 918 in awell known manner. Removable storage unit 918 represents a floppy disk,magnetic tape, optical disk, etc., which is read by and written to byremovable storage drive 914. As will be appreciated, removable storageunit 918 includes a computer usable storage medium having stored thereincomputer software and/or data.

In alternative implementations, secondary memory 910 may include othersimilar means for allowing computer programs or other instructions to beloaded into computer system 900. Such means may include, for example, aremovable storage unit 922 and an interface 920. Examples of such meansmay include a program cartridge and cartridge interface (such as thatfound in video game devices), a removable memory chip (such as an EPROM,or PROM) and associated socket, and other removable storage units 922and interfaces 920 which allow software and data to be transferred fromremovable storage unit 922 to computer system 900.

Computer system 900 may also include a communication interface 924.Communication interface 924 allows software and data to be transferredbetween computer system 900 and external devices. Examples ofcommunication interface 924 may include a modem, a network interface(such as an Ethernet card), a communication port, a Personal ComputerMemory Card International Association (PCMCIA) slot and card, etc.Software and data transferred via communication interface 924 are in theform of signals 928 which may be electronic, electromagnetic, optical,or other signals capable of being received by communication interface924. These signals 928 are provided to communication interface 924 via acommunication path 926. Communication path 926 carries signals 928 andmay be implemented using wire or cable, fiber optics, a phone line, acellular phone link, a radio frequency link, or any other suitablecommunication channel. For instance, communication path 926 may beimplemented using a combination of channels.

In this document, the terms “computer program medium” and “computerusable medium” are used generally to refer to media such as removablestorage drive 914, a hard disk installed in hard disk drive 912, andsignals 928. These computer program products are means for providingsoftware to computer system 900.

Computer programs (also called computer control logic) are stored inmain memory 908 and/or secondary memory 910. Computer programs may alsobe received via communication interface 924. Such computer programs,when executed, enable computer system 900 to implement the presentinvention as discussed herein. Accordingly, such computer programsrepresent controllers of computer system 900. Where the invention isimplemented using software, the software may be stored in a computerprogram product and loaded into computer system 900 using removablestorage drive 914, hard disk drive 912, or communication interface 924,to provide some examples.

In alternative embodiments, the invention can be implemented as controllogic in hardware, firmware, or software or any combination thereof.

The embodiments above are described by way of example, and are notintended to limit the scope of the invention. Various alternatives maybe envisaged which nevertheless fall within the scope of the claims. Aswill be apparent from the above discussion, the method can be performedusing a 2D image having a single CT slice, or a 3D image havingconsecutive CT slices.

CONCLUSION

Example embodiments of the methods, systems, and components of thepresent invention have been described herein. As noted elsewhere, theseexample embodiments have been described for illustrative purposes only,and are not limiting. Other embodiments are possible and are covered bythe invention. Such other embodiments will be apparent to personsskilled in the relevant art(s) based on the teachings contained herein.Thus, the breadth and scope of the present invention should not belimited by any of the above described exemplary embodiments, but shouldbe defined only in accordance with the following claims and theirequivalents.

1. A computer-implemented method of displaying a computed tomography(CT) scan image, comprising: a) processing a scan image using a filterto generate an enhanced scan image in which one or more featuresindicative of an abnormality are enhanced and at least one feature ofthe scan image is obscured; and b) displaying the scan image and theenhanced scan image to enable a visual comparison of the scan image andthe enhanced scan image. 2-18. (canceled)